Presentation (CTI)

OBJECTIVES: Transthyretin amyloid cardiomyopathy (ATTR-CM) is caused by the cardiac deposition of misfolded transthyretin (TTR). It is frequently misdiagnosed as other cardiac conditions, postponing treatment with disease-modifying therapies like tafamidis, a TTR stabilizer. This study estimates the proportion of patients within a tafamidis-treated ATTR-CM experiencing delayed diagnosis.
METHODS: We conducted a retrospective cohort study using 2018-2022 Merative MarketScan® Commercial Claims and Medicare Supplemental database. The index date was defined as the date of the first tafamidis prescription among patients with at least two tafamidis pharmacy claims ≥30 days apart. A lookback period of at least one year with continuous enrollment was established to determine delayed diagnosis. Delayed diagnosis was defined as having at least one inpatient or at least two outpatient diagnoses of selected cardiac conditions commonly considered in the differential diagnosis of ATTR-CM preceding the index date. The outcome was the proportion of patients with delayed diagnosis indicated by differential diagnoses preceding tafamidis initiation. Logistic regression evaluated the association of age and sex with delayed diagnosis.
RESULTS: Among 505 eligible patients, 86% were Medicare-insured. Diagnostic delay was observed in 55% of the cohort. Commercial enrollees had higher odds of delay compared with Medicare beneficiaries (adjusted odds ratio [aOR] 1.24; 95% CI 0.75-2.08). Females were less likely to experience diagnostic delay compared to males (aOR 0.65;95% CI 0.42-1.02). Among commercial enrollees, heart failure (25.8%), cardiomyopathy (23.3%), and ischemic heart disease (18.3%) were the most common misdiagnoses, whereas arrhythmias (24.6%), heart failure (23.2%), and ischemic heart disease (22.2%) predominated among Medicare enrollees.
CONCLUSIONS: Delayed diagnosis of ATTR-CM was common and was not associated with age or sex. Heart failure and ischemic heart disease were the most common preceding diagnoses regardless of insurance type. Improved recognition of ATTR-CM among patients presenting with heart failure or ischemic heart disease may help reduce diagnostic delays.